Botasy blower



J T, NEEDHAIVL ROTARY BLOWER.

APPLICATION FILED IUNES. 1916. RE

REWED JAN 29.1919,

Pateniedffij Q, 1919.

N TOR fl w w A J. T. NEEDHAIVI.

ROTARY BLOWER. APPLICATION FILED JUNES. 1916- RENEWED 1mm 1019 1 y 3 1 5 23% I Patented Sept. 9, 1919.

3 SHEETS-SHEET 2.

A TTORNE VS 3. T. NEEDHAM ROTARY BLOWER.

APPLlCATlOnI FILED JUHEB 1916 RENHIED JAN 29-1919 atent 1Sept.9,1919.

3 SHEETS-SHEET 3.

' INVET r A I ll'hl PATEN @hhllQhh JOHN '1. NEEDHAM, OF BAYON N E, NEW 3' ROTARY BLOWER.

Application filed June 8, 1916, Serial No. 102,395.

To all whom it may com-( 7m:

Be it known that 1, JOHN T. NEEDHAM, a subject of the King of Great Britain, a citizen of Canada, and resident of Bayonne, county of Hudson, and State of New Jersey have invented certain new and useful Improvements in Rotary Blowers, of which the following is a. specification.

This invention relates to that class of rotary blowers in which two intermeshing rotors are employed within a suitable inclosing casing, said rotors impelling the air through the discharge port at one side of the Casing and drawing it through the inlet at the other side of the casing. The shape and operation of these rotors are well known and need not be particularly described herein. Th present invention relates more particularly to the arrangement of the rotors and to the construction and arrangement of the parts of the blower as awhole.

I make no claim herein to anything claimed in my copending application Serial No. 874,637. filed Nov-ember 30, 191st, in which is illustrated and claimed a blower comprising a casing formed with an upper compression chamber and a lower oil chamber directly under the compression chamber and separated therefrom by a horizontal wall, a pair of rotor shafts extending vertically through said oil chamber and into the compression chamber, rotors on the upper ends of-said shafts in the compression chamber. a worm gear connected to each of said rotor shafts in the oil chamber, and a single driving worm arranged between the rotor shafts with its axis perpendicular to the axes of the rotor shafts, said driving worm directly engaging the worm gears and driving the rotor shafts in opposite directions.

One of the main objects of the invention is to provide a blower wherein the rotors or impellers will'be in a compression chamber at the top of the casing and the driving mechanism will be mounted in an oil chamher at the bottom of the casing. a free air space being; formed between the said two chambers in order to prevent oil creeping; up the rotor shaft-s from the'oil chamber into the compression chamber. In blowers of this type it is important, to keep the oil from the compression chamber, and it has been found that by arranging an air space between the compression chamber and the oil chamber, and leaving said space open to the Specification of Letters Patent.

Patented Sept. $1 19159. Renewed January 29, 1919. Serial No. 273,886.

atmosphere, oil will not creep up the rotor shafts beyond the air space.

Another object of the invention is to sur round the compression chamber by a jacket or shell, forming an air space, and to provide means for forcingair through said space in suificiont quantities to maintain the walls of the compression chamber cool. This is desirable where this type of blower is used to produce heavy pressures.

Another object of the invention is to providethe rotor shafts with intermeshing locking gears in order to maintain the rotors in their proper relative positions with .respect to each other. It has been found in blowers of this type, that the worms and worm gears wear, with the result that the rotors are shifted slightly with respect to each othen This interferes with the efficiency of the apparatus. This defect is overcome bymeans of the locking gears shown and described herein.

There are other advantages of the invention, due to the peculiar coi'istruction and arrangement of the parts, all of which will be fully hereinafter described.

In the drawings, Figure 1 is a vertical sectional View;

Fig. 2 a horizontal sectional view on the line H-H of Fig. l;

Fifi, a side elevation, the jacket or shell forming the air space around the blower frame being shown in se-ctionalview, and the plate closing one end of the oil well being removed;

Fig. 4 a vertical sectional. view on the line lV-lIV of Fig. and

Fig. 5 a plan view of the blower. the inclosing jacket or shell being shown in horizontal sectional View.

' Referring to the various parts by numerals, 1 designates an electric motor for driving the blower. This motor may be of any suitable construction, and its shaft is dircctly connected to the dr ving shaft of .the blower.

The blower consists of a casing and support 3' formed with a compression chamber 4 at its upper end, and with an oil chamber 5 at its lower end. In the compression chamber are arranged the two rotors or impellers 6, which are adapted to be rotated in opposite directions as indicated by arrows in Fig. 5, the air beinp drawn in throne-h passage 7 and forced. out through passage 8 in the usual manner of air 'c'oinpressors or blowers of this type. The compression chamber is closed by a top plate or cover 9. The bottom of the compression chamber is formed by a vall and the top of the oil chamber is formed by a horizontal wall 11 spaced a suitable distance below the bottom of the compression chamber. The space or chamber 12 between the two horizontal walls 10 and 11 is open to the atmosphere, as shown at 1.3 in Fig. 3, so that said chamber Will be fully and freely ventilated and there can be no accumulation of oil therein. This air chamber forms a free air space between the oil chamber 5 and the compression chamber, and prevents oil creeping up the rotor shafts into the compression chamber.

The rotors or impellers are mounted on the upper ends of vertical shafts 14 which extend through the bottom of the compression chamber and through the oil chamber, as clearly shown in Fig. 1 of the drawing. Each shaft 14 is mounted in antifriction roller bearings, one of said bearings, 15, being arranged in the cover plate; one, 16, being arranged in the top wall 11 of the oil chamber, and one, 17, being arranged in the bottom wall of said, chamber. Each shaft, therefore, is provided with three bearings, the impellers 6 being mounted between the bearings 15 and 16. The driving gears, which will be hereinafter described, are connected to the shaft between the bearings 16 and 17. The bearing 16 is mounted in a bushing 18 fitted in the wall 11 and secured in place therein by means of a nut ring 19. The said bushing is provided with a dust ring 20 having a yieldable. surface adapted to bear on the shaft to prevent the entrance of dust or dirt into the bearing, and also assisting in'prevcnting the passage of oil upwardly on the shaft. The ball bearing 16 may he of any desired form but a. bearing designed to take radial and endwise thrusts is preferred. The bearing 15 is mounted in a bushing cap 15 fitted in the cover plate. The bearing 17 is mounted in a lmshing 21 titted in the bottom wall of the chamber The bushings 15 and 17 form caps to close the openings in the bottom walls and top, and cover the upper and lower ends of the shafts. The purpose of mounting the bearings 15, 16 and 17 in bushings is that when said bearings become worn they may be readily removed and new bearings adjusted therein,

On each rotor shaft, within the oil chamber 5 andbetwern the bearings 16 and 17', is secured a worm gear Between the two rotor shafts is arranged a horizontal driving shaft 2, on which is mounted the worm 23, sa d worm engaging the worm gears on the iotor shafts and driving one of them in one direction and the other in the opposite direction. W ith this arrangement of worm and gears the rotor shafts are driven simultmie ously. at the same speed. and in o posite directions. The worm and worm gears. arranged as described, serve as sprawl-reducing means, thereby dispensing with intermediate speed-reducing gears between the motor shaft and the shafts of the impellers. On each rotor shaft, between the upper bearing 16 and the worm'gear 22. is threaded-a thrust ring or sleeve 24, said sleeve engaging the underside of the bearing 10. Above the bearing 16 each rotor shaft is provided with a shoulder 11 said shoulder engaging the upper surface of the bearing. lltlk'll locking gear is additionally keyed to its rotor shaft by a transverse key 25. The lower end of each rotor shaft is shouldered to engage the upper surface of the bearing 17. Each worm gear '22 is formed with an annular recess 26 on its lower side, which is adapted to receive a cylindrical hub 27 formed on a locking gear 28. A groove 29 is formed'in the upper sin-face of said locking gear to receive a depending annular flange 30 formed on the bottom of the worm gear 22. The worm gears are formed in two half-sections which areadapted to be brought together around the rotor shaft, the said sections being then bolted to the hub 27 of the locking gear by means of stud bolts 31. The worm gear and the locking gear are then securely keyed to the rotor shaft by means of a cross pin The object of forming the worm gears in sections is to permit of their ready removal and the replacement of new gears, should said gears become Worn or broken. By forming them in sections as described, they may be removed without dismantling the entire apparatus.

The locking gear 28 of one rotor shaft meshes with the corresponding locking gear of the other rotor shaft. The purpose of providing these locking gears is to insure the proper positioning of the impellers with respect to each other, and to maintain them in their proper relations. Without these locking gears. which receive little or no strain and consequently will be imperceptibly worn, the impellers will be slightly changed in their relation to each other as the worm gears wear. It is manifest that by providing the locking gears the rotor shafts and the rotors will be maintained in proper relation. notwithstanding any wear on the worm gears and the Worm.

The oil chamber 5 is formed with the openings 33 through opposite side walls, one of said openings being closed by a plate EH. This plate carries inwardly extending horizontal arms 35 which are connected togetlna' at their inner ends by a verticalplate 36. The driving shaft is supported in antifriction bearings 37 carried by the end plates 3% and 36, the driving worm '23 being mounted on said shaft between said bearings. As shown clearly in Fig. l, the plate 3i and the plates connected to and carried thereby,

form a supporting frame for the drive shaft :2, said frame being supported in position by the bolts which connect the plate 34 to the main blower frame 3. It is manifest that by disconnecting the plate 34 from the blower frame, the driving shaft and the worm and the supportin frame may be removed from the-oil cham 381, By mounting the driving shaft and the worm in this independent supporting frame the assembling of the parts may be completed before the frame inserted in the oil chamber. The side of the oil chamber opposite the plate 3 closed by a plate 38, said plate carrying a filling cup 39, the upper end of said cup being closed by a plate 40. By removing plate ll) the height of the oil in the oil chamber may be noted, and the said chamber may be filled or charged.

To prevent the heating of the walls of the compression chamber the said walls are provided with outwardly extending vertical ribs ll spaced a suitable distance apart around the said chamber, as shown clearly in 3 and Surrounding the compression chamber and the cooling ribs 41, is a jacket or shell 42, the lower end of said jacket extending somewhat below the compression chamber, and being o clearly in Figs. 1 and 3." 1 tends over the top of the com her and tefminates in a substantially circular opening centrally over the compression chau'iber. Mounted in this open ing a fan or blower 44, said fan being mounted on a short vertical shaft journaled in the top plate 9. Mounted on this shaft small pinion i6 which meshes with a larger gear 47 secured to one of the rotor shafts. ft is manifest that as the rotors are operated the fan will. be driven to draw air upwardly through the shell around the con'ipressiou chamber and between the ribs thereof, and out through the central opening This circulation of air will prevent the heating of the walls of the compression chamber and also prevent the heating of the top plate 9. This plate is preferably formed with vertical ribs 48 to provide an additional radiating surface therefor.

The jacket or shell 42 is preferably formed of two halves secured together by belts or rivets 49, as cl ariy shown in Fig. 5 of the drawings. This facilitates the assembling of the parts, but it will, of course, be understood that it may be made in any suitable manner or in any desired number of sections.

What 1 claim is:

l. A lower comprising a casing formed with a compression chamber at its upper end and on oil. chamber at its lower end, an air space being formed between said chambers, a pair of vertically arranged rotor shafts extending through said chambers and the air space, rotors on the ends of said shafts in the compression chamber, a worm gear connected to each of said shafts in the oil oil chamber, a worm gear connected to eachof said shafts in the oil chamber, and a driving Worm arranged between and directly engaging both of said worm gears.

3. A blower comprising a casing formed with a compression chamber at its upper end having a bottom wall and an oil chamber at its lower end having both a bottom wall and a top wall, a pair of vertical rotor shafts extending through said chambers, a removable cover plate for the top of the compression chamber, bearings for each of said shafts in the cover plate and in the top and bottom walls of the oil chamber, a worm gear connected to each of said shafts in the oil chamber, and a driving worm arranged between and directly engaging both of said worm gears.

4. A blower comprising a casing formed witha compression chamber at its upper end having a bottom wall and an oil chamber at its lower end having both a bottom wall and a top wall. an air space being forn'ied between said chambers and open to the atmosphere, a pair of vertically arranged rotor shafts extending through said ,chan1- bers and the air space, hearings in the top and bottom walls of the oil chamber for said rotor shafts, rotors on the ends of said shafts in the compression chamber. and a driving mechanism connected to said shafts in the oil chamber.

5. A blower comprising a casing formed with a con'ipression chamber at its upper end and an indepcni'lent chamber near it lower end, a pair of vertically arranged rotor shafts extending through said chamhers, means in the lower chamber for driving said shafts, a jacket or shell surrounding the upper part of the casing to form an air space. and means at the top of said jacket or shell to draw air upwardly therethrough and around the compression chamber.

6. A blower comprising a casing formed with a compression chamber at its upper end hating a top wall and an independent chamber near its lower end, a pair separated vertically arranged rotor shafts extending through said chambers, means in the lower chamber for driving said shafts, a jacket or shell snrroumling the upper partof the casing to form an air space, and means for forcing air through the jacket or shell and around the compression chamber, said means consi. ting of a fan carried by a short vertical shaft stepped between said rotor shafts, a gear thereon, and a meshing gear on the extended end of one of the rotor shafts.

T. A blower comprising a casing formed with a compression chamber at its upper end and an independent chamber near its lower end, a pair of vertically arranged rotor shafts extending through said chambers, means in the lower chamber for driving said shafts, outwardly extending ribs formed on said casing at its upper end, a jacket or 'shell surrounding the upper part of the casing to form an air space, and means at the top of said jacket or shell to draw air upwardly therethrongh and around the compression chamber.

3. A, blower comprising a casing formed with a. compression chamber at its upper end and an independent chamber near its lower end, a pair of vertically arranged rotor shafts extending through said chambers, means in the lower chamber for driving said 'shafts, outwardly extending ribs formed on said casing at its upper end, a jacket or shell surrounding the upper part of the casing to form an air space, a'fan at the top of said shell, and means connecting said fan to one ofthe rotor shafts to draw air upwardly through the shell and around the compression chamber.

9. A blower comprising a casing formed with a compression chamber at its upper end and an independent chamber at its lower end. a pai of vertically arranged rotor shafts extending through said chambers, rotors on the ends of said shafts inthe compression chamber, a. worm gear connected to each of said shafts in thelowcr chamber, a driving worm arranged between and directly engaging both of said worm gears, and a pair of intermeshing locking gears carried by said shafts and locking them together to maintain the rotors in their proper relative positions.

10. A blower comprising a casing formed with a compression chamber at its upper end and an independent chamber at its lower end, a pair of vertically arranged rotor shafts extending through said chambers, rotors on the ends of said shafts in the compression chamber. a worm year connected to rotor shafts extending through said cham bers, rotors on the ends of said shafts in the compression chamber, a worm gear connected to each of said shafts in the lower chamber, each of said gears being formed with an annular socket in its under side, a driving worm arranged between and directly engaging both of said worm gears, a pair of locking gears, each of said gears being formed with a hub on its upper side adapted to fit in the annular socket in one of the worm gears, said locking gears inter-meshing to maintain the rotors in their proper relative positions, and means for rigidly connecting each worm gear to one of the locking gears.

12. A blower comprising a Casing formed with a compression chamber at its upper end and an independent chamber at its lower end, a pair of vertically -.irranged rotor shafts extending through said. chambers, rotors on the ends of said shafts in the compression chamber, a divided worm gear connected to each of said shafts in the lonier chamber, adriving worm arranged between and directly engaging both of said worm gears, and a'pair of intcrmeshing locking gears carried by said shafts and locking them together to maintain the rotors in their pro-per relative positions.

13, A blower comprisin with a compression ehaiiitt r at its upper end and an independent chamber at its lower end, a pair of vertically arranged rotor shafts extending through said chambers, rotors on the ends of said shafts in the compression chamber, a worm gear connected to each of said chamber, a driving worm arranged l'ietween and directly engaging both of said worm gears. a supporting frame for said worm, and a closure plate connected to said frame and adapted to be secured to the side of the casing to close thc sidc of the lower chamber, whereby the driving worm and the frame will be suppoi fed on said closurc plate.

In testimony \x'hercof I hereunto affix my signature.

JOHN T. n'nnnnaiul a casing formedshafts in the lower 

